The studies outlined in this proposal are designed to prepare the PI, Dr. Kathleen Markan, with the technical and intellectual expertise required to become an expert in beige adipocyte development and metabolism. Specifically, Dr. Markan will perform in vivo metabolic phenotyping studies and perform ChIP-seq analysis and functional screening of putative TBX1 target genes using adipocytes isolated from the novel adipocyte specific TBX1 mouse models she has generated. Beige adipocytes display a tremendous capacity for energy expenditure and their biology is being actively studied as a potential means to treat human obesity meaning, Dr. Markan?s work will provide direct insights regarding processes that could be used to treat human obesity. With these goals in mind, the following studies are proposed: 1) determine if TBX1 adipocyte expression is both sufficient and necessary for the development of beige adipocytes by phenotyping TBX1 adipocyte-specific transgenic mice under lean and diet induced obese conditions and testing the ability of TBX1 adipocyte-specific knockout mice to defend core body temperature during a cold challenge. This application was thoughtfully designed to allow Dr. Markan to transition her work into independence and progress to tenure-track faculty status at the end of the award period. The work outlined above will be conducted by Dr. Markan under the supervision of her mentor Dr. Matthew Potthoff, Assistant Professor of Pharmacology and co-mentor Dr. Dale Abel, Director of the F.O.E. Diabetes Research Center and Chair of Internal Medicine, both at the University of Iowa. Dr. Markan will also be strongly supported and her progress closely monitored through direct and regular engagement with her team of collaborators and consultants. Through this K01 award, Dr. Markan will expand her technical and scientific knowledge base, acquire new skills and generate data that will lead to her success as an independent academic scientist. Both the Department of Pharmacology and the F.O.E. Diabetes Research Center at the University of Iowa provide a rich environment for conducting the proposed studies and Drs. Potthoff and Abel as well as the Department of Pharmacology are strongly committed to Dr. Markan?s success.